Synthetic grass implants for marking grassed or sodded surfaces comprising a body to be set up in the ground and having artificial grass blades protruding above the ground surface, are known, for example, from U.S. Pat. No. 9,147,150, WO 95/12441 and WO02008068296A1, all incorporated herein by reference.
WO 95/12441 discloses an implant/marker comprising a body to sink into the ground, on which are fixed blades of artificial grass. The upper part of the body is installed flush with the ground surface and the lower portion is pointed, its general shape is generally conical. The placement of the implant and its replacement is very easy and does not need to prepare the soil or digging because of its small size. It does not interfere with the traffic of people and vehicles on the marked surface.
The filaments of such devices are usually made from a polymeric material having, after obtaining the desired thickness of the filaments (a few tenths of millimeters to one or two millimeters), the characteristics of rigidity and flexibility to that they are prepared to rest and he bowed to the passage of a user of the land marked without risking injury to the user or damage to the device. Another feature of these devices is that the filaments are resilient and return to their position immediately after the passage of the user.
These devices, originally designed to be implanted on grassy surfaces and guide each tracing land boundaries, such as sports, are proving to be useful for other applications, in particular to provide various marking delineations on the ground. For example locations for campsites, the boundaries of a park or visualizing a path could be achieved by such devices.
Although such prior art implants/markers are very well suited for marking points or even lines in the top surface of grassed areas, they are less useful in marking underground features such as underground electrical lines, underground water, sewer or gas pipes, or other underground or hidden from view features or devices.
Although these prior art markers may provide a visual top surface indication that there is some feature or device located/buried nearby or underneath the marker, the marker does not provide any detailed information such as, for example, what the device or feature is; how deep the device or feature is; how big it is; how long it is; what date it was installed or the like. For such underground or hidden devices or features, it would be advantageous and desirable to have a very detailed information about what the implant/marker is marking.
Prior attempts at incorporating an electronically activatable device such as an RFID tag or the like within the implant/marker have not always been successful. It is sometime difficult to produce an implant/marker that can keep the RFID electronics dry and secure. In addition, an RFID tag that is small enough to be inserted into the center of the implants/markers discussed herein do not have very large antennas and therefore have very limited range.
Accordingly, what is needed is a synthetic grass implant/marker that serves as a surface mounted visual marker for a feature or device located nearby or underground and has all the features and advantages of such a synthetic grass implant, and that additionally includes a device such as an externally attached RFID tag or chip that can programmed with information concerning the feature or device it is marking, and which information can be obtained by utilizing an RFID reader to obtain the stored information from the implant/marker. Such a device should also have a large coil antenna to facilitate the reading and writing of the data to the RFID device.